Vertical movement and persistence of granular insecticides in soil

Phorate, quinalphos and carbofuran residues were detected in soil below the plough depth layer (6-9") as well as in the upper layers. Aldicarb was localised mainly in the 0-3" and 3-6" layers. The persistence of phorate and quinalphos residues in all three layers was higher than that of carbofuran and aldicarb.